I just took an internet hollidays for a few weeks 🙂 but came back with lots of new ideas for posting.
At Micofora we manage hundreds of truffle orchards and their technical visits allow us to have a wide catalog of pests and diseases that arise, and their potential treatments.
I attached a couple of pictures, one of a small snail that this year has infested some plantations, especially when you mow the grass, then snails come up to the tree trunk or even micro-sprinklers, completely blocking them. In this case a treatment that worked, was based on metaldeid (commercial product Cargol-mat), spreading a teaspoon in the base of the tree trunk and the water will dissolve it and will make its effect. Moreover, the effect will last in later irrigations.
On the other hand this canker or tumor was affecting a high percentage of the trees of a truffiere. Many of them died and though as you see some sprout below the bulge, the tree is severely damaged. According to experts these cankers are caused by phytoplasmas (a kind of bacteria) whose treatment is quite complex. Others are produced by drilling insects (easy to see their larvae galleries when we cut the trunk). Some of them are caused by the beetle Cerambyx, with long antennae, which is a plague in many oak forests in Spain. In fact summer is optimum for biological control of the adults, which can be attracted by simple traps with mashed melon, water and citric acid. For more information please read these documents in spanish (you will also get an idea of the traps used by the pictures without a translation):
All the best,
Marcos S. Morcillo